Sildenafil acts primarily by inhibiting phosphodiesterase activity to treat erectile dysfunction in men, which is the indication for sildenafil.
The pharmacological action (i.e. the mechanism of action of the drug) of Sildenafil (full name is Sildenafil Citrate) is mainly to inhibit the activity of phosphodiesterase, so that the cyclic guanosine phosphate in the tissues will be increased, so that the smooth muscle of the small penile arteries and the penile cavernous body smooth muscle will be relaxed, and the localized blood flow in the tissues will be elevated, so as to achieve the purpose of treating male erectile dysfunction.
In the process of using sildenafil, it may also bring some discomfort to the patient, which is an adverse drug reaction, all drugs have adverse reactions, but it does not happen to all people. When experiencing an adverse reaction, you should talk to your doctor and pharmacist.
The common adverse reactions of sildenafil are headache, flushing, dizziness, nasal congestion, dyspepsia, visual abnormalities, etc.; rare are facial edema, shock, fatigue, pain, rash, tachycardia, palpitations, hypotension, postural hypotension, etc.; very rarely, sudden loss of vision in one or both eyes, persistent erection for more than 4 hours, sudden onset of hearing loss or loss.
If you are taking morphine, nitrate drugs (such as nitroglycerin, isosorbide mononitrate), you can not take sildenafil at the same time. The combination can enhance the antihypertensive effect of the above drugs and lead to low blood pressure. Please be sure to take it properly under the guidance of your doctor.